Ruby: Fix some Ql4Ql violations.

ruby/ql/lib/codeql/ruby/ApiGraphs.qll

@@ -1,5 +1,5 @@
 /**
- * Provides an implementation of _API graphs_, which allow efficient modelling of how a given
+ * Provides an implementation of _API graphs_, which allow efficient modeling of how a given
  * value is used by the code base or how values produced by the code base are consumed by a library.
  *
  * See `API::Node` for more details.

ruby/ql/lib/codeql/ruby/frameworks/core/Kernel.qll

@@ -50,7 +50,7 @@ module Kernel {
   }
 
   /**
-   * Private methods in the `Kernel` module.
+   * Holds if `method` is a name of a private method in the `Kernel` module.
    * These can be be invoked on `self`, on `Kernel`, or using a low-level primitive like `send` or `instance_eval`.
    * ```ruby
    * puts "hello world"

ruby/ql/lib/codeql/ruby/frameworks/http_clients/Excon.qll

@@ -25,27 +25,28 @@ private import codeql.ruby.DataFlow
  */
 class ExconHttpRequest extends Http::Client::Request::Range instanceof DataFlow::CallNode {
   API::Node requestNode;
-  API::Node connectionNode;
   DataFlow::Node connectionUse;
 
   ExconHttpRequest() {
     this = requestNode.asSource() and
-    connectionUse = connectionNode.asSource() and
-    connectionNode =
-      [
-        // one-off requests
-        API::getTopLevelMember("Excon"),
-        // connection re-use
-        API::getTopLevelMember("Excon").getInstance(),
-        API::getTopLevelMember("Excon").getMember("Connection").getInstance()
-      ] and
-    requestNode =
-      connectionNode
-          .getReturn([
-              // Excon#request exists but Excon.request doesn't.
-              // This shouldn't be a problem - in real code the latter would raise NoMethodError anyway.
-              "get", "head", "delete", "options", "post", "put", "patch", "trace", "request"
-            ])
+    exists(API::Node connectionNode |
+      connectionUse = connectionNode.asSource() and
+      connectionNode =
+        [
+          // one-off requests
+          API::getTopLevelMember("Excon"),
+          // connection re-use
+          API::getTopLevelMember("Excon").getInstance(),
+          API::getTopLevelMember("Excon").getMember("Connection").getInstance()
+        ] and
+      requestNode =
+        connectionNode
+            .getReturn([
+                // Excon#request exists but Excon.request doesn't.
+                // This shouldn't be a problem - in real code the latter would raise NoMethodError anyway.
+                "get", "head", "delete", "options", "post", "put", "patch", "trace", "request"
+              ])
+    )
   }
 
   override DataFlow::Node getResponseBody() { result = requestNode.getAMethodCall("body") }

ruby/ql/lib/codeql/ruby/frameworks/http_clients/NetHttp.qll

@@ -27,11 +27,10 @@ private import codeql.ruby.DataFlow
 class NetHttpRequest extends Http::Client::Request::Range instanceof DataFlow::CallNode {
   private DataFlow::CallNode request;
   API::Node requestNode;
-  API::Node connectionNode;
   private boolean returnsResponseBody;
 
   NetHttpRequest() {
-    exists(string method |
+    exists(string method, API::Node connectionNode |
       request = requestNode.asSource() and
       this = request and
       requestNode = connectionNode.getReturn(method)

ruby/ql/lib/codeql/ruby/regexp/internal/ParseRegExp.qll

@@ -194,7 +194,7 @@ abstract class RegExp extends Ast::StringlikeLiteral {
   }
 
   /**
-   * Holds if the character set starting at `charset_start` contains a character range
+   * Holds if the character set starting at `charsetStart` contains a character range
    * with lower bound found between `start` and `lowerEnd`
    * and upper bound found between `upperStart` and `end`.
    */

ruby/ql/lib/codeql/ruby/security/ImproperMemoizationQuery.qll

@@ -45,7 +45,7 @@ private class MemoCandidate extends Method {
 }
 
 /**
- * Holds if parameter `p` of `m` is read in the right hand side of `assign`.
+ * Holds if parameter `p` of `m` is read in the right hand side of `a`.
  */
 private predicate parameterUsedInMemoValue(Method m, Parameter p, MemoStmt a) {
   p = m.getAParameter() and
@@ -54,7 +54,7 @@ private predicate parameterUsedInMemoValue(Method m, Parameter p, MemoStmt a) {
 }
 
 /**
- * Holds if parameter `p` of `m` is read in the left hand side of `assign`.
+ * Holds if parameter `p` of `m` is read in the left hand side of `a`.
  */
 private predicate parameterUsedInMemoKey(Method m, Parameter p, HashMemoStmt a) {
   p = m.getAParameter() and